After reading a few articles on the topic of lighting-up model buildings I’ve got a plan but thought it would be worthwhile to explain it here to see if I’m on the right track and to ask if there is any other advice on aspects that I haven’t thought of.



My plan is to have about 20 to 25 buildings of different types on my HO scale layout and I’d like to light them all from inside.  Already existing is a 12V DC bus which provides power for a turntable motor and for a short narrow-gauge railway that runs from a station on the DCC-powered main line. My thinking is to tap into this bus at three locations and to run a feed to each of the three “towns” on the layout.



Each town will have five to ten buildings and the plan is to wire those buildings as a town group with a potentiometer to control each town group.  The three potentiometers will allow differing levels of lighting from one town to another.



In each of the three towns some buildings will have two interior lights (say, a double-story pub) or a two-roomed station building (waiting room and office) and so there might be 40 to 50 individual lights.



My impression from what I’ve read and seen is that LEDs are better than other forms of lighting because they don’t heat-up and there’s no danger of melting fittings.  As for colour, it seems that warm white LEDs will give the best lighting effect.  I’m aware that I might need resistors if I use LEDs, depending on the type used.



I might also install 10 to 12 street lights but perhaps they would be best on a separate circuit – not sure about that.



That’s my plan.  Questions that I have are:

1.    Is 12V DC the best type of power supply for interior lighting?

2.    If so, would a separate power supply be better than tapping into the existing one?

3.    Are potentiometers the best way to adjust lighting levels?

4.    If potentiometers are best, are there any necessary specifications that they should have?

5.    Are LEDs the best way to provide lighting?

6.    If so, is warm white the best colour?

7.    If resistors are required, does each LED need a resistor or could one resistor serve a town group of LEDs?

8.    If one resistor would serve a group, would it be in the circuit before or after the potentiometer?

9.    How important is viewing angle of the LEDs?  (I see LEDs advertised with viewing angles of 15 to 120 degrees.)

10. Is there any other advice that could be useful?



Thanks in advance for any responses.

After reading a few articles on the topic of lighting-up model buildings I’ve got a plan but thought it would be worthwhile to explain it here to see if I’m on the right track and to ask if there is any other advice on aspects that I haven’t thought of.

My plan is to have about 20 to 25 buildings of different types on my HO scale layout and I’d like to light them all from inside.  Already existing is a 12V DC bus which provides power for a turntable motor and for a short narrow-gauge railway that runs from a station on the DCC-powered main line. My thinking is to tap into this bus at three locations and to run a feed to each of the three “towns” on the layout.

Each town will have five to ten buildings and the plan is to wire those buildings as a town group with a potentiometer to control each town group.  The three potentiometers will allow differing levels of lighting from one town to another.

In each of the three towns some buildings will have two interior lights (say, a double-story pub) or a two-roomed station building (waiting room and office) and so there might be 40 to 50 individual lights.

My impression from what I’ve read and seen is that LEDs are better than other forms of lighting because they don’t heat-up and there’s no danger of melting fittings.  As for colour, it seems that warm white LEDs will give the best lighting effect.  I’m aware that I might need resistors if I use LEDs, depending on the type used.

I might also install 10 to 12 street lights but perhaps they would be best on a separate circuit – not sure about that.

That’s my plan.  Questions that I have are:

1.    Is 12V DC the best type of power supply for interior lighting?

2.    If so, would a separate power supply be better than tapping into the existing one?

3.    Are potentiometers the best way to adjust lighting levels?

4.    If potentiometers are best, are there any necessary specifications that they should have?

5.    Are LEDs the best way to provide lighting?

6.    If so, is warm white the best colour?

7.    If resistors are required, does each LED need a resistor or could one resistor serve a town group of LEDs?

8.    If one resistor would serve a group, would it be in the circuit before or after the potentiometer?

9.    How important is viewing angle of the LEDs?  (I see LEDs advertised with viewing angles of 15 to 120 degrees.)

10. Is there any other advice that could be useful?



Thanks in advance for any responses.

Hi Parksider,

Here are my thoughts:

1. 12v is as good as any voltage to drive LEDs from, if that's what you have lying around use it.

2. I would use a separate one, no real need to, but there is a chance your turntable etc moving could cause your town lights to dim.

3. Yes and no, yes you will certainly use a potentiometer if you want to adjust brightness, but you will ned some other componentry in order to achieve the result you are looking for.

4. I would have a look around in Jaycar etc and see what they can offer you in a kit, look for a variable voltage source or sometimes it might be called a motor speed controller. It will give you some knowledge of electronics and how it's going to do it's job as you build it.

5. Yes.

6. Probably yes.

7. One resistor per LED please.

8. Attached directly to the LED, after all your control circuitry.

9. It's not especially, but the wider the angle the less 'spotlight ish' it will look, you might also investigate cutting/filing the rounded end off the LEDs taking them back to a flat front to help remove some of the spot-lightness.

10. You've nailed most of the questions.

Don't forget to get the polarity of the LEDs correct as you install them.

If you don't want to adjust the brightness of the lights, you can just connect the individual LEDs and their resistor to your 12v. You can still have variable brightnesses within or between your towns by varying the resistor value. For 12v don't use less than 560 ohms, but anything up to lots like 5k (5000) ohms will give you something more dim, there is a chance that some LEDs will be very dimly lit with a 10k ohm resistor from 12v, some may not work, but the resistor is going to cost you 4c to test it out...

I bow to Aaron's knowledge and agree with what he has said.

I don't know how much these potentiameters are likely to cost you, but as an alternative option, have you considered supplying the power via a cheap (2nd hand) DC train controller? These come up on ebay all the time and you could (if you want) have a separate controller for each town.

Example: http://www.ebay.com.au/itm/Power-Mite-240V-12V-DC-Lima-Model-Railway-Power-Controller-Transformer-HO-N-OO-/190862542506?pt=AU_Toys_Hobbies_Model_Railways&hash=item2c704b46aa&_uhb=1

Also, it may be possible to use some old mobile phone chargers (or similar) as your power supply. Some of these have quite low voltage/amperage outputs, but not sure about the regulation of output.

Roachie